Printing means using electric fields



April 7, 1953 F. c. PETHICK 2,633,796

mmm MEANS USING ELECTRIC FIELDS Filed April 5, 1944 3 Sheets-Sheet lINVENTOR 46 F812 D C. PEI-max.

F511- BY ATT RNEY April 7, 1953 g, PETHICK 2,633,796

PRINTING MEANS USING ELECTRIC FIELDS Filed April 5, 1.944 3 Sheets-Sheet2 a o. 3 w I ATT 0 EY A ril 7, 1953 F. c. PETHICK 2,633,796

PRINTING MEANS USING ELECTRIC FIELDS Filed April 5, 1944 3 Sheets-Sheet3 IO a 20 I/Z 6 FLEJEJ- Ella-LE1- INVENTOR Hm 9 CT Prrmck mNEY PatentedApr. 7, 1953 PRINTING MEANS USING ELECTRIC FIELDS Ford C. Pcthick,Englewood, N. J., assignor to R. Hoe & 00., Inc., New York, N. Y., acorporation of New York Application April 5, 1944, Serial N 0. 529,595

This invention relates to a novel method and means for printing, andmore specifically refers to depositing ink through the influence of anelectric field.

The invention contemplates as its principal object, the provision of amethod and means for printing which does away with the necessity ofinking type before an object can be printed therefrom.

Another object of the invention is to provide a method and means fortransferring ink directly from an ink supplying mechanism to thematerial to be printed.

Another object of the invention is to provide a new and improvedmechanism from which ink can be transferred directly to the material tobe printed.

Another object of the invention is to provide a means to limit theportion of the web or sheet on which ink may be deposited.

Still another object of the invention is to provide a new type ofprinting plate.

Other and further important objects of the invention will becomeapparent from the following description and the appended claims.

In accordance with the invention, as herein shown, a travelling web ofpaper is passed between a plate carrying form cylinder and an inksupplying mechanism. Due to forces set up by an electric field, ink isremoved from the ink supplying mechanism and deposited on the web inaccordance with a design carried by the form cylinder. For a morecomplete understanding of the invention, reference should be' had to theaccompanying drawings in which:

Figure 1 is a perspective view of a portion of a printingmachineembodying the principles of the invention;

Figure 1A is an electrical diagram showing a method of supplyingelectric power to the printingunit shown in Figure l; Figure 2 is anenlarged cross sectional view of a portion of the printing unit shown inFigure l; Figure 3 is a fragmentary view similar to a portion of Figure2 and depicting a modified form of printing plate; 7

Figure 4 is a perspective view of portions of a 3 Claims. (01. 101-212)Figure 9 is an enlarged view of the ink supplying mechanism shown inFigures 8 and 10; and

Figure 10 is a view, showing a further development of the form of theinvention depicted in Figure 8.

Referring to the drawings, the invention has been shown in one form inFigures 1, 1A and 2 as applied to a web printing machine comprising aform or type cylinder H), which cooperates with a guide roller ll aboutwhich a sheet or web 12 of paper or other suitable material is led. Theform cylinder I0 is rotatable on a shaft l3 and carries a printing formor plate l4 having a design formed by raised, sharp-edged type 15intermingled with depressions IS. The plate M may be constructedaccording to usual practices, except, that the letters, numerals, andother designs appearing on the surface thereof, should be direct readingin place of reversed as is the practice with present day newspaper andmagazine plates.

As illustrated in Figure 1, the web 12 passes over the guide roller Hand about the lower portion of the form cylinder l0. As illustrated, asurface I9 of the web I2 is in contact with the form or plate 14, whilea surface 20 of the web is exposed.

A means for printing on the exposed side 20 of the web l2 has beenprovided adjacent to the exposed side thereof, and includes a pluralityof atomizer type ink supplying mechanisms 2|, each having an enclosedink reservoir 22, and an insulated ink supply tube 23. Preferably ink iscaused to rise in the tubes by means of air pressure supplied to thereservoir by way of an air duct 24. An air blast from insulated nozzles25 cooperates with each insulated ink tube, to atomize the ink and toproduce an ink mist. A means 21 for electrifying the ink spray or mistis positioned directly in front of the atomizer 2|, and in theembodiment of the invention illustrated in Figures l, 1A- and 2,comprises a fine wire 28 positioned parallel to the axis of the cylinderIll and located parallel to and between a .pairof parallel cylindricalrods 29. A high voltprinting machine showing a modifledfonn-of theinvention; s Figure- 5 is an enlarged cross sectional view taken throughthe line 5-5 of Figure 4, and lookingin the direction-of the arrows;

Figure 6 is a view similar to Figure 5, but

showing .theformpcylinder in a slightly advanced position;

vFigure 7..is a fragmentary cross sectional view showing anothermodified form of the invention; Figure 8is a yiew showing a printingmachine equipped. with .;a modifled..fprm.;of.ink supplying mechanism;

age source oi -direct currents!) is connected between the wire 28 androds 29, the wire 28 pref- :erably being charged positively with respectto the rods 29 which may be maintained at ground potential.

As particles of ink in the ink mist pass the highly charged wire '28,they acquire a positive electrical charge and form a positively chargedink mist 30a. A shield 3|, having a flared portion 32, is positionedconcentric with the form cylinder 10 and preferably is spaced one-eighthto one-half an inch therefrom. The atomizer 2| .and the electrifyingmechanism 21 are positioned :sothat, the stream of electrified ink mist30a is .:dir.ected toward. the. space 33 between. the exposed side 20 orthe web l2, and the shield ll.

3 The shield 3| is highly charged positively with respect to the formcylinder I5, which may be maintained at ground potential.

One method of electrifying various portions of the equipment is shown inFigure 1A wherein the wire 28, and shield 3| are shown connected to apositive terminal 34 of the high voltage electrical source 30 by aconductor 35. The negative terminal 33 of the source 30 is grounded asat 39. Rods 29 and the cylinder 20 are grounded by conductors 40 and 4|respectively.

The high voltage which is applied between the positively charged shield3| and the negative form cylinder It causes a strong electric field tobe formed therebetween. As the positively charged particles of the inkmist 36a enter this electric field, they are repelled by the positiveshield 3| and attracted by the negative plate $4, with the resultthatink is deposited on the lower surface 25 of web I2 in accordance withthe design carried on the plate I4. Since any face 42 of the type orother design I5 is closer to the shield 3| than are the bottoms of thedepressions of the web I2 and a new design on the plates I4 are rotatedinto the electric field defined by the shield 3|, and this results inthe web I9 being printed as it passes over the form cylinder I5.

Figure 3 shows amodified form of printing plate I4 in which thedepressions I6, between the raised portions I5 of the type are filledwith an insulating material 48 having a high dielectric constant.Placing this material in the depressions I6 is equivalent to increasingtheir depth, and helps to concentrate the electric field, and thus theink on the area of the web opposite the face 42 of the type or otherdesign. The modified form of plate I4 shown in Figure 3 of course may besubstituted for the plate I4 shown in Figure 2.

-A modified form of theinvention is illustrated in Figures 4, 5 and 6wherein the web I2 is forwarded by being passed underneath the roller Ii and then over the top of the form cylinder I0. An ink supplyingmechanism 53 is located close to and above the rotatable form cylinderIll. The cylinder 15 and its shaft I3 carry a concentric cam 54, havingtwo low portions 58 and two high portions 59. A cam follower 60 engagesthe cam 54 to control'an electric switch 6|, the function of which ishereinafter described. The ink supplying mechanism 53, supported onproper insulators (not shown), may consist of a hopper or V-shapedmetallic box 5| having a cover 62, and an opening or slot 63 atthebottom thereof, whereby ink mist 64, produced in the ink supplyingmechanism 53, may bedeposited on the face 2|) of the web I2. Preferablythe box 5| may contain a plurality of ink spray nozzles 65 arranged toproduce the ink mist 54. Pipes 61 and 68, containing proper insulatingjoints (not shown), may be employed to supply air and ink to the mistproducing nozzles. Due to the force of gravity and the air pressureproduced in the box 5| by the spray nozzles, the ink mist 54 is expelledthrough the opening 53. As best illustrated in Figures 5 and 6, theopening 63 is equipped on both sides with sharp edged troughs 89.running lengthwise of the box 5|, which through connecting pipes (notshown), carry away any liquid ink which may form on the inside of box5|. Opening 53 is also equipped with a knife shaped electrode I2supported at 13, running lengthwise of the opening 63, and preferablyspaced equi-distant between the two troughs 69. Preferably a highpotential source of directcurrent 36 is controlled by contactor I4. Themetallic box 5| of the ink supplying mechanism 53 may be connected toone contact 15 of the contactor I4 by means of electrical conductor I8,and the other contact of the contactor 14 may be connected to thepositive terminal 34 of source 30 by conductor 85.

The negative terminal of source 30 and the form cylinder it are groundedby means of conductors 39 and 4| respectively. Solenoid 8|, whichoperates the movable contact of contactor I4, is connected to oneterminal of a control power source 52 by means of a conductor 83 and toone terminal of the switch 5| by a conductor 84. The other terminal ofthe switch 6| is connected to the second terminal of the control powersource 82 by a conductor 85. The low portions 58 of the cam 54 arepositioned opposite the margin bars 88, located between the edges of thetwo plates I4. Thus when the cam follower 50 follows into the lowportions 53, the switch BI is opened and the solenoid 8| of thecontactor I4 is deenergized, with the result that the high potentialsource 35 is disconnected from the ink supplying mechanism 53 during theperiod while the margin bars 88 pass the opening 53 in the box 5|. Thisassures that irregularities caused by the margin bars 88 and the edge ofthe plate I4 will not appear as printing on the web I2. It will beunderstood that an electronic contactor having proper grid control canbe substituted for the magnetic contactor 14. As in the previouslydescribed embodiment of the invention, ink from the ink supplyingmechanism is deposited on the side 20 of web I2 opposite from the sideI9 which contacts the form I4 and the electric field which isestablished between the ink supplying mechanism 53 and the form cylinderin controls the particles of ink mist 64, with the result that ink isdeposited on the web I2 in accordance'with the design carried by theform or plate I4. The particles of the ink mist 64 which leave thepositively charged ink supplying mechanism 53 carry a positiveelectrical charge and thus are repelled by the box 5| and are attractedby the negatively charged plate I4 and cylinder I0.

As the form cylinder IIJ rotates to carry the plate I4 past the opening63 in the box 5|, the electric field which exists between the box 5| andthe face 42 of the form I4 varies as the design on the form or platevaries. This phenomenon is illustrated in Figures 5 and 6 where thedesign carried on the plate I4 is shown in two different positions withrespect to the knife 12 and opening 63. I

A further modification of the invention is illustrated in Figure 7 inwhich a plurality of atomizers 2| (only one of which is shown), haveparts formed from insulating material similar to the atomizer 2| shownin Figure 2, and spray atomized ink past the positively charged wire 28located between the rods 29, which are similar to the wire 28 and therods 29 shown in Figure 2. The ink mist 35a which is electrified afterpassing the wire 28, passes between a positively charged knife typeelectrode 92and the negatively charged printing plate 14. The electriclines of force existing between the electrode 92 and the plate itcontrols the ink mist so that it is deposited on the exposed face 2c ofthe web 12 in accordance with the design carried by the plate Id. Acollection system consisting of an exhaust pipe a reclamation tank 9:.having baffles s5, and a suction pipe at, has been provided in order toremove any excess ink mist 30a which is not deposited on web l2.

A still further modification of this invention is shown in Figures 8, 9and in which another type of ink supplying mechanism its is employed.The web it is passed over a roller II and under a form cylinder it whileelectrical energy is supplied from the high potential source 3?} and thecontrol source 82 in a manner similar to that shown in Figure 4. One ofthe differences being that the switch 61 is located above the cam 54,and that the ink supplying mechanism Hit is positioned below the formcylinder It. The ink supplying mechanism ice is connected to thepositive terminal 34 of high voltage source and is insulated from roundby post type insulators Iiil. A motor 52 drives a pair of rollers M3 bymeans of belt its and pulleys 195. The two large rollers Hi3 and a smallroller H16 are mounted on a frame its in the form of a triangle andcarry a wide belt I07 having bristles I08 protruding from the outersurface thereof. The lower part of the rollers Hi8 and the portion ofthe belt Hi1 stretched therebetween are immersed in a tray H Icontaining a supply of ink. As the belt I6! travels over the threepulleys it carries ink from the tray II I to a point I I2 close to theexposed surface 2!! of the web 12. The high potential electric fieldwhich exists between the roller I06 and the plate I4 carried by cylinderi8 transfers ink from the bristles I68 to the exposed surface 20 of theweb :2. Since the small particles of ink on the ends of bristles I88 arepositively charged, they are repelled by the positively charged rollerH16 and attracted by the negatively charged plate It and thus the web [9is printed in a manner similar to the method hereinbefore described.

The embodiment shown in Figure 10 is similar to that shown in Figures 8and 9 except that a plurality of separate ink supplying mechanisms MA,[MB and I680 are spaced around the periphery of the plate cylinder [0.Each ink supplying mechanism is associated with a switch 61A, BIB, and610, a contactor MA, MB and 140, a high potential power source 36, and acontrol power source 82; all being similar to those previouslydescribed. By means of these mechanisms it is possible to apply morethan one application of ink to the web as it passes over the formcylinder 10. For example, as the web 12 passes around the lower half ofform cylinder I0, it receives an initial printing as it passes by theroller IDEA of ink supplying mechanism of 100A, and as the same portionof the web passes ink supplying mechanism 18313 and IBIC it receives asecond and third printing. It will be understood that the same design isprinted by all three ink supplying mechanisms with the result that thedesign printed will be more intense than a design formed by oneprinting. The switches BIA, 61B and GIC cooperate with the ink supplyingmechanisms WA, 18813 and 1000 respectively to deenergize theirrespective high voltage source at the instant that the margin bars 88pass by the rollers IDEA, IOSB and 106C respectively.

It will be understood that the invention may be embodied in otherspecific forms, as for example, it can be arranged to print sheets inplace of a web, without departing from the spirit or essentialattributes thereof, and it is therefore desired that the illustratedembodiments be considered in all respects as illustrative and notrestrictive.

What I claim is:

l. A printing unit for printing on a sheet comprising in combination aform cylinder, a printing plate mounted on the form cylinder andarranged to contact one side of the sheet, at least one ink supplyingmechanism, and a means for producing an electric field between the inksupplying mechanism and the plate; the said ink supplying mechanismcomprising in combination an ink tray, a travelling belt having amultiplicity of bristles and being arranged to transfer ink from thesaid ink tray to a point adjacent to the side of the sheet which is notin contact with printing plate.

2. In a web printing unit comprising in combination a form cylinderhaving a design carried by a plate arranged to contact one side of asheet of material, at least one ink supplying mechanism, and a means forproducing an electric field between the said ink supply mechanism andthe plate, and a means for deenergizing the electric field producingmeans when the edge of the plate is in the neighborhood of the inksupplying mechanism; the said ink supplying mechanism comprising incombination a tray, a travelling belt having a multiplicity of bristlesand being arranged to transfer ink from the said ink tray to the pointadjacent to the side of the material which is not in contact with theplate.

3. A printing unit for printing on a sheet or web and comprising incombination a form cylinder, a printing plate mounted on the formcylinder and arranged to contact one side of the sheet or Web, at leastone ink supplying mechanism, and a means for producing an electric fieldbetween the ink supplying mechanism and the plate, the said inksupplying mechanism comprising in combination an ink tray, a travelingbelt having a multiplicity of bristles capable of supplying ink in theform of small particles and arranged to transfer ink from the said inktray to a point adjacent to the side of the sheet or web which is not incontact with the printing plate.

FORD C. PETHICK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 767,684 Burdick Aug. 16, 19041,217,250 Wensel Feb. 27, 1917 1,763,731 Whittaker June 1'7, 19301,820,194 Huebner Aug. 25, 1931 2,224,391 I-Iuebner Dec. 10, 19402,408,144 Huebner Sept. 24, 1946 2,451,288 Huebner Oct. 12, 1948 FOREIGNPATENTS Number Country Date 214,669 Great Britain 1924

